A COMPARISON OF TIME TO EXHAUSTION AT (V)OVER-CIRCLEO(2) MAX IN ELITECYCLISTS, KAYAK PADDLERS, SWIMMERS AND RUNNERS

A recent study has shown the reproducibility of time to exhaustion (ti me limit: tlim) at the lowest velocity that elicits the maximal oxygen consumption (vV over dot O(2)max). The same study found an inverse re lationship between this time to exhaustion at vV over dot O(2)max and vV over dot O(2)max among 38 elite long-distance runners (Billat et al . 1994b). The purpose of the present study was to compare the time to exhaustion at the power output (or velocity) at V over dot O(2)max for different values of V over dot O(2)max, depending on the type of exer cise and not only on the aerobic capacity. The time of exhaustion at v V over dot O(2)max (tlim) has been measured among 41 elite (national l evel) sportsmen: 9 cyclists, 9 kayak paddlers, 9 swimmers and 14 runne rs using specific ergometers. Velocity or power at V over dot O(2)max (vV over dot O(2)max) was determined by continuous incremental testing . This protocol had steps of 2 min and increments of 50 W, 30 W, 0.5 m s(-1) and 2 km(-1) for cyclists, kayak paddlers, swimmers and runners , respectively. One week later, tlim was determined under the same con ditions. After a warm-up of 10 min at 60% of their vV over dot O(2)max , subjects were concluded (in less than 45 s) to their vV over dot O(2 )max and then had to sustain it as long as possible until exhaustion. Mean values of vV over dot O(2)max and tlim were respectively equal to 419+/-49 W (tlim=222+/-91 s), 239+/-56 W (tlim=376+/-134 s), 1.46+/-0 .09 m s(-1) (tlim=287+/-160 s) and 22.4+/-0.8 km h(-1) (tlim=321+/-84 s), for cyclists, kayak paddlers, swimmers and runners. Time to exhaus tion at vV over dot O(2)max was only significantly different between c ycling and kayaking (ANOVA test, p<0.5). Otherwise, V over dot O(2)max (expressed in ml min(-1)kg(-1)) was significantly different between a ll sports except between cycling and running (p<0.05). In this study, time to exhaustion at vV over dot O(2)max was also inversely related t o V over dot O(2)max for the entire group of elite sportsmen (r=-0.320 , p<0.05, n=41). The inverse relationship between V over dot O(2)max a nd tlim at vV over dot O(2)max has to be explained, it seems that tlim depends on V over dot O(2)max regardless of the type of exercise unde rtaken.